Thursday, October 29, 2009

Test tiles

Ahhhhh, test tiles.  What a pain the tush.  But so necessary.

I try out so many glazes and very few of them actually look how they look on the test tiles and color charts at the store.  Especially since I sometimes use white clay and other times use a dark red. 

I didn't want to use up a ton of clay and I wanted my tiles to be easily accessible so I could see my collection at a glance.  I also wanted to see how the glazes show or hide impressions and how it breaks over edges.  And I wanted the tiles to sit vertically in the kiln so I could see how much they run and flow.  Here's what I came up with.

I use an extruder die designed to make handles.  It's flat on one side and a nice gentle curve across the other.  I squirt out my long noodles and cut them to lengths of 4-5 inches.

Then I roll over each one with a rolling rubber stamp to make impressions on the rounded side.  And just so I have more flexibility in how I display them later, I punch a hole at the end of each one with one of my kemper hole cutters. 

As greenware, they take up very little space in the kiln.  I generally toss them into a mug or something for the first firing.

It's kind of hard to see in this picture but this is one of the stands I made for the glaze firing.  It's a wad of clay, about an inch and a half round ball.  When it's leather hard, I smack it into the table to make a nice flat edge.  Then I dig out the center to create a stand for the tile to sit in.  I want the hole to be about an inch deep so that the tile doesn't topple over in the kiln.

When I'm ready to test a new glaze, I put a number on the back (the flat side) near the hole with an underglaze pencil.  The hole will be the end that goes into the holder.

Holding the hole, I dip the majority of the tile into the glaze and hold for a count of 3.  When that dries, I dip it again but only about 2 inches.  On the third dip, I just dip the top inch.  This shows me what the glaze looks like at different thicknesses and just how thick it needs to be to give me the color I want.  This also puts the majority of the glaze at the very end so if it's runny, it has more room to run before it seals itself into the holder.

As you can see, when it's fired, it takes up very little space in the kiln.  And if the glaze is runnier than I expected, it should run either into the cup holding the tile, or onto the outside of it.  It might ruin the tile and the holder, but it doesn't ruin the kiln shelf.

Forgot to mention, when I make each tile, I write down the glaze info in a little booklet.  The number on each tile corresponds to the info in the booklet so when I get the tile back out of the kiln, I can look up which glaze goes with which tile.  I also have a central database with this info on my computer in case the labels get mixed up or something later on.

So look at all the information I have on this one little tile - obviously the color and texture of the glaze, whether or not the stamped impressions will show through, what the glaze will look like given the opportunity to run, how it breaks over a rim, what it looks like on a rounded and flat surface, will it drip beyond the line it's applied to, will it look differently if the coat I put on is uneven.  And since I do each glaze in a white and a red test tile, will the color of the clay affect the color of the glaze.

Then to display the tiles, I put some velcro on the back of each one and attach it to a piece of, oh crud, I can't think of the name of that board.  Foam core, that's it!  Foam core.  They don't sit perfectly flat (they warp in the kiln a little bit) but eh, close enough for government work.

The white tiles go on one side and the colored tiles go on the other so I can quickly look over all of the colors of glazes according to color of clay the piece is made of.   

I made labels with my handy dandy label maker and labeled each tile with the glaze color.  In my database, I also have info on the manufacturer and the code number of the glaze in case they change the name in the future.  And because you never know if two manufacturers are going to use the same name.

With this display set up, it's very easy to toss them into an old briefcase and set the aside when I don't need them.  It's also easy to pick up one tile to look at it with another one to see if the two colors would look good together or to directly compare them.  And when I run out of a glaze that I don't intend to replace, I toss the two corresponding tiles into an old mug in a drawer.  That way I have the info if I want to consider buying that glaze in the future, but I'm not looking at it as a possibility for a piece if I don't actually have any of that glaze available at the moment.

Next post will talk about a test tile system for testing various combinations together which I'm stealing from a new friend of mine.

And just for good measure, and because he was sitting there waiting for me when I went into the studio to take these pics, here's a shot of Buster hiding from the rain in the studio.


Anonymous said...

Great ideo for test tiles. I can't wait to try out your idea! Just curious, do you keep your tile holder (wad of clay) to use in future firings or do you make new holders every time?

AlexMMR said...

I have about 20 that I use over and over.